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以三聚氰胺(M)、水杨酸(SA)和甲醛(F)为原料,亚硫酸氢钠(SB)为磺化剂,采用四步合成法制备了SMSAF(磺化三聚氰胺-水杨酸-甲醛树脂)高效减水剂。系统探讨了合成工艺条件对SMSAF减水剂分散性的影响。研究结果表明:当n(M)∶n(SA)∶n(F)∶n(SB)=1∶0.1∶3.9∶1.3,羟甲基化阶段的反应温度为70℃、反应时间为1 h和p H为8.5,磺化阶段的反应温度为85℃、反应时间为3 h和p H为12,酸性缩聚阶段的反应温度为60℃、反应时间为1 h和p H为4,碱性重整阶段的反应温度为85℃、反应时间为1 h和p H为8.5时,合成的SMSAF减水剂综合性能良好;当w(SMSAF)=1.0%(相对于水泥质量而言)时,混凝土体系具有良好的分散性,水泥净浆初始流动度(达249 mm)相对最大。
Using melamine (M), salicylic acid (SA) and formaldehyde (F) as raw materials and sodium bisulfite (SB) as sulfonating agent, SMSAF (sulfonated melamine salicylate formaldehyde Resin) superplasticizer. The effect of synthesis conditions on dispersion of SMSAF superplasticizer was systematically investigated. The results show that when the reaction temperature is 70 ℃ and the reaction time is 1 h at n (M): n (SA): n (F): n (SB) = 1: 0.1: And p H is 8.5, the reaction temperature in the sulfonation stage is 85 ° C., the reaction time is 3 h and the p H is 12, the reaction temperature in the acidic polycondensation stage is 60 ° C., the reaction time is 1 h and the pH is 4, the basicity When the reaction temperature was 85 ℃, the reaction time was 1 h and the pH was 8.5, the synthesized SMSAF water reducer showed good overall performance. When SMSAF = 1.0% (relative to the mass of cement) The concrete system has a good dispersion, the initial flow of cement paste (up to 249 mm) is relatively maximum.